1. Field of the Invention
The present invention relates to drag reducing devices for commercial vehicles. More specifically, the present invention provides a drag reducing device comprising an inflatable member disposed on a foldable frame securable to a rear portion of a tractor trailer or similar commercial vehicle for the purpose of reducing drag and turbulent air flow on the rear portion of the vehicle.
The fuel efficiency of a commercial vehicle is limited by several factors including friction from the wheels, changes in grade, power train losses, and aerodynamic drag. Aerodynamic drag is one of the largest determining factors of the vehicle's fuel efficiency, and improving the aerodynamics of a vehicle can result in substantial improvements in fuel efficiency.
As a truck drives along a road, the truck encounters air resistance or drag from the air flowing around the truck. The oncoming airflow creates a high-pressure region at the front of the vehicle, while a low-pressure region is created at the rear of the vehicle, impeding the movement of the vehicle. The drag decreases the fuel efficiency of the vehicle, and drag increases as the vehicle moves at increasing speeds. Thus, a device for improving the aerodynamics of a vehicle, particularly a tractor trailer, and that can be stored while not in use is desired.
2. Description of the Prior Art
Devices have been disclosed in the prior art that relate to drag reducing devices for vehicles. These include devices that have been patented and published in patent application publications. These devices generally relate to inflatable members securable to the rear of a tractor trailer or similar vehicle for reducing drag. The following is a list of devices deemed most relevant to the present disclosure, which are herein described for the purposes of highlighting and differentiating the unique aspects of the present invention, and further highlighting the drawbacks existing in the prior art.
One such device, U.S. Pat. No. 6,789,839 to Samuelson discloses a wind dam for use with tractor trailers. The device comprises an inflatable cone-shaped wind dam for reducing drag on the tractor trailer. The wind dam includes two longitudinally opposed sections each having an outer shell and an inflatable bladder. The cone shaped wind dam includes an inflatable mating joint for maintaining the shape of the wind dam. Thus, Samuelson fails to disclose a drag reducing device having a hinged frame removably securable to the rear portion of a tractor trailer.
Another device, U.S. Pat. No. 4,601,508 to Kerian discloses a streamlining appendage for a vehicle. The device comprises a rearwardly tapering peripheral body defining a chamber. An opening is provided that allows air flow to pass therethrough and out of the rearward end of the vehicle. Thus, the device serves to dissipate the partial vacuum that forms behind a vehicle while in motion. However, Kerian fails to disclose a device having a hinged frame with an inflatable member supported thereon.
U.S. Pat. No. 2,737,411 to Potter discloses an inflatable streamlining apparatus for vehicles. The device includes an inflatable member having a streamlined construction securable to the rear portion of a tractor trailer or similar vehicle. The device includes retracting means for rolling the inflatable member for storage. Thus, Potter discloses an inflatable streamlining device, but fails to disclose a hinged frame having two sections that support an inflatable member thereon.
U.S. Pat. No. 4,978,162 to Labbé discloses a drag reducer for the rear end of a vehicle. The drag reducer includes a piece of flexible material adapted to fit tightly around the periphery of the rear of a truck. The piece of material displays a convex surface when fully extended. The material includes openings thereon such that movement of the truck causes air to flow into the device causing it to inflate. Thus, Labbé discloses a device that inflates as the truck moves, and does not disclose a device that allows the user to control inflation and deflation thereof.
U.S. Pat. No. 4,741,569 to Sutphen discloses an inflatable drag reducer for a vehicle. The device can be attached to the rear doors of the vehicle and can be inflated to form an apex at the rear thereof. The device can be flattened or deflated so as to allow easy access to the rear of the vehicle. Thus, Sutphen discloses an inflatable drag reducer, but fails to disclose a hinged frame securable to the rear of the vehicle.
Finally, U.S. Pat. No. 6,467,833 to Travers discloses a drag reducer. The device includes a frame hinged to the rear of a vehicle and an inflatable bag secured thereon. The inflatable bag includes at least two converging panels defining a drag reducing structure. Thus, Travers fails to disclose a frame having a pair of hinged sections that supports an inflatable member thereon, wherein the inflatable member tapers to a point at the rear portion thereof.
These prior art devices have several known drawbacks. The devices in the prior art variously relate to drag reducing structures for commercial vehicles, such as tractor trailers. However, such devices may limit access to the rear of the vehicle and cannot be easily arranged in a stored configuration. Further, the devices do not include a frame having a pair of hinged sections that allows the inflatable member to be concealed within the frame for storage.
In light of the devices disclosed in the prior art, it is submitted that the present invention substantially diverges in design elements from the prior art and consequently it is clear that there is a need in the art for an improvement to existing drag reducing devices for commercial vehicles. In this regard the instant invention substantially fulfills these needs.